<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>两栏布局</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        html,body,div{
            height: 100%;
        }
        .box1{
            width: 200px;
            background: yellow;
            float: left;
        }
        .box2{
            background: red;
            margin-left: 200px;
        }
    </style>
</head>
<body>
    <div class="box1"></div>
    <div class="box2"></div>
</body>
</html>